In the pouring and dispensing of a liquid from a container, such as the dispensing of motor oil or windshield cleaning solution or anti-freeze from a container of blow-molded plastics material, it is common to use a funnel to prevent spillage of the liquid when the container is inverted. However, sometimes a pouring spout is used in place of the funnel, and the spout is usually attached by an annular nut to the threaded annular neck portion of the container defining the outlet. Examples of pouring spouts for liquid containers are disclosed in U.S. Pat. No. 4,129,236, No. 4,664,301 and No. 4,832,238. As disclosed in these patents, the pouring spouts are molded of a rigid or semi-rigid plastics material and may incorporate a flexible bellows-like portion and an internal closure valve, for example, as disclosed in U.S. Pat. No. 4,832,238.